Memory backspace device for printing apparatus



United States Patent 13,537,564

[72] Inventor James M. Huckabee 1,243,955 10/1917 Krusius 197/91Lexington, Kentucky 2,872,014 2/1959 Khalil 197/91X [21] Appl. No.683,258 3,346,086 10/1967 Cralle et a1. 197/84 [22] Filed Nov. 15,19673,417,849 12/1968 Terenzani..., 197/91 [45] Patented Nov. 3, 1970 Primary I l y Examiner-Ernest T. Wright, Jr. [73] Asrs'gnee 22:22:32 BusinessMachmes Attorneys- Frank C. Leach, Jr. and Hanifin and Clark Armonk, NewYork I a corporation of New York ABSTRACT: The device includes meansmovable with a por- 54 MEMORY BACKSPACE DEVICE FOR PRINTING (1011 Of thetypewriter that moves during each actuation of a APPARATUS key of thetypewriter. After the movable means has been 4 Chims, 5 Drawing Figs.rnoved a selected amount, the movable meansis returned to I ts startingposmon. When the movable 1118311818 moved from [52] US. Cl. 197/9l itsstarting position. a resihemly biased |atch is positioned to [51] 19/62retain a backspace lever in a position for repeat operation [50] FieldolSearch 197/84(Cur), when the backspace lever is moved to a position inwhich it 1 1 80 may be retained by the latch. Whenever the movable meansis returned'to its starting position, the latch is moved to a non- [56]Rem-anus citgd retaining position. Thus, the device may providebackspacing UNITED STATES PATENTS for a previously typed character in aproportioned spacing 928,591 7/1909 Delvigne 197/91 typewriter or to thestart of a previous word in any typewriter.

Patented No .3,1 970 Sheet 1 of 2 JAMES M. HUCKYABEE .w BY M c, M

ATTORNEY MEMORY BACKSPACE DEVICE FOR PRINTING APPARATUS SPECIFICATION lntypewriters having proportional spacing of the characters whereby thewidth of each character is designed in accordance with its naturalwidth, the spacing for each of the characters is not the same. Forcharacters having a small natural width, the space of the type characteris small in comparison with characters having a large natural width.

Therefore, when his desiredto backspace a character or a plurality ofcharacters with a proportional spacing typewriter, the typist isrequired to know the number of units assigned to each character. Forexample, an i" would have a width of two units while an "1" would have awidth of four units. Thus, if the typist wished to backspace in aproportional spacing typewriter, it is necessary to backspace two unitswhen the character is an i and four units when m" is the character.

As a result of this requirement of the typist to remember the units ofwidth of each of the characters of the typewriter, there has been areluctance on the part of sometypists to use a proportional spacingtypewriten Therefore, the proportional spacing typewriter has beenlimited, to a degree, in its utilization.

The present invention satisfactorily overcomes the foregoing problemwhereby the device ofthe present invention does not require the typistto remember the number of units of width of each of the characters.Instead, the memory backspace device of the present invention merelyrequires the typist to depress the backspace lever to a second levelposition where it isheld by retaining means of the memory device untilrelease after the required amount of backspacing has occurred.

Furthermore, the memory device of the present invention s'till permitsthe typist to backspace only a single unit of spacing whenever desired.Thus, the memory device of the present invention not only eliminates therequirement for the typist to know the units of width of each of thecharacters of a proportional spacing typewriter but also allows thetypist to still have single unit backspacing when desired. A

It has previously been suggested in U.S. Pat. No. 928,591 to Delvigne toutilize a backspace memory device in which the typist could backspaceautomatically to the beginning of a word, i.e., to where a previousactuation of the space bar lever had occurred. In this type ofarrangement, a rotating pin wheel structure has been employed. However,this rotating pin wheel structure has been rather complicated andrelatively expensive. Furthermore, this rotating pin wheel structureisnot adaptable for use in a proportional spacing typewriter in whicheach of the characters has varying units of width.

Thus, the present invention is an improvement over the previouslysuggested memory backspace device utilizing the rotating pin wheel. Thememory device of the present invention is not only much simpler inconstruction-and, therefore, relatively inexpensive. but it also may beutilized to permit selectively backspacing only a single character or aword.

In the previously suggested rotating pin wheel memory I backspacedevice, the pin prevents any additional backspacing beyond the pin.Thus, the typist could not backspace to any position but is limited tothat defined by the pin.

The present invention satisfactorily overcomes the foregoing problemsince the typist can backspace any amount. Thus, backspacing is notlimited to the typed word as in the previously suggested rotating pinwheel memory backspace device.

Additionally, in the previously suggested rotating pin wheel memorybackspace device, separate backspace keys were required for singlebackspace and word backspace. The present invention permits the use ofonly a single backspace key for either single unit backspacing, singlecharacter backspacing, or word backspacing.

In the memory backspace device of the present invention, means isprovided to automatically erase the previously stored escapementinformation concerning the character or word in the memory device assoon as the next character is selected or when the space bar means isactuated. Furthermore, the present invention contemplates erasing thestored memory of escapement information concerning the character or wordin response to various function operations of the typewriter such astabulation or carriage return, for example.

An object of thisinvention is to provide a memory backspace device toregulate the amount of backspace of a printing apparatus in accordancewith the width of the previously printed character or word.

Another object of this invention is to provide a linear memory backspacedevice that permits normal single unit backspacing when, the backspacelever is moved to a first position and controlled automatic back spacingin accordance with the stored memory of the prior typed character orword when the backspace lever is moved to a second position.

A further object of this invention is to provide a memory backspacedevice that is relatively inexpensive and may be easily added to atypewriter. V

The foregoing and other objects, features, and advantages of theinvention will be more apparent from the following more particulardescription of the preferred embodiments of the invention as illustratedin the accompanying drawing.

In the drawing:

FIG. 1 is a schematic perspective view of one embodiment of the memorybackspace device of the present invention and taken from the rear ofatypewriter.

FIG. 2 is a schematic perspective view of a portion of the backspacemechanism utilized with the device of the present invention.

FIG. 3 is a schematic perspective view of another portion of thebackspace mechanism,

FIG. 4 is a schematic perspective view of another form of the memorybackspace, device of the present invention and taken from the rear of atypewriter.

FIG. 5 is a schematicperspective view ofa modification of a portion ofthe device of FIG. 1.

Referring to the drawing and particularly FIG. I, there is shown amovable member 10 of a typewriter. In a typewriter having typebars forprinting characters, the movable member I0 may be attached to thecarriage bed, for example, which moves with the platen supporting thepaper upon which printing occurs as the platen moves relative to areference position at which each character is printed by its typebar.The movable member 10 functions as a movable letter feeding part.

The memory backspace device of the present invention ineludes a memorybracket 11 having a memory lever 12 universally mounted thereon, and thememory lever I2 has a friction member 14 supported on one end thereofwith a surface 15 of the friction member 14 engaging the bottom of themovable member I0. The friction member 14 is preferably formed ofasuitable friction material such as asbestos filled rubber, for example,that will cause the memory lever 12 to follow the movement of themovable member 10 to the right until the memory lever 12 engages a stop16 on the bracket 11 or to follow the movement ofthe member 10 to theleft until the memory lever 12 engages a second stop I7 on the memorybracket 11. When the lever 12 engages either of the stops I6 and 17depending on the direction of movement of the movable member 10, thefriction member 14 permits the movable member 10 to continue to moverelative to the memory lever 12.

The memory bracket 11, which is fixedly secured to a fixed portion ofthe typewriter, has a flange 18 disposed parallel to main surface 19 ofthe memory bracket 11 and in spaced relation thereto. A block 20 ispivotally mounted between the flange 18 and the main surface 19 by a pin21.

The block 20 pivotally mounts the memory lever 12 thereon by a pin 22,which is disposed substantially perpendicular to the pin 21, whereby thememory lever 12 may pivot about the axis of the pin 22. Since the block20 may pivot about the axis of the pin 21, the memory lever 12 isuniversally mounted on thebrackct ll.

The memory lever I2 is biased upwardly and to the left by a spring 23.The movement to the left is in the direction of backspace movement. Thespring 23 has one end secured to a downwardly depending finger 24 on thememory bracket 11 and its other end secured to a horizontally upstandingfinger 25 on the memory lever 12.

Thus, the spring 23 serves to continuously urge the surface 15 of thefriction member 14 into engagement with the movable member 10. At thesame time, the spring 23 continuously urges the lever 12 against thestop 17. The force of the spring 23 is overcome by the movement of themovable member 10 as the paper is moved relative to the referenceposition at which the characters are typed.

The typewriter has a backspace lever 26, which is pivotally mounted on arod 27 fixed to the frame of the typewriter. The front end of thebackspace lever 26 extends through a slot 28 in a front guide comb 29,which is fixed to the typewriter. The backspace lever 26 is continuouslyurged upwardly (as viewed in FIGS. 2 and 3) about the rod 27 by a spring30, which has one end connected to the front end of the backspace lever26 and its other end connected to a projection 31 (see FIG. 3) on thefront guide comb 29 with the projection 3i disposed vertically above theslot 28.

A plunger 32 is continuously urged against the bottom surface of theguide comb 29 by a spring 33, which has its lower end bearing on aprojection 34 on the lower portion of the front guide comb 29. The lowerend of the slot 28 is open in the same manner as is shown for a slot 35in the front guide comb 29. Thus, when the backspace lever 26 isdepressed through actuation of its keybutton 36, the backspace lever 26may move through the slot 28 and move the plunger 32 downwardly againstthe force of the spring 33 from a first level position to a second levelposition. The upper end of the plunger 32 is U-shaped to cooperate withthe front guide comb 29 to be moved only vertically.

The backspace lever 26 is connected through a cam assembly 37 (see FIG.2), which is fulcrumed on a rod 38 that is fixedly secured to thetypewriter, and an operating link 39 to a backspace mechanism. If thememory backspace device ofthe present invention is being utilized with aconventional typebar typewriter in which each of the characters has thesame type width, the backspace mechanism is preferably of the type shownand described in pages 99 to I03 oflBM Customer Engineering InstructionManual for Standard Typewriter, Model C-l, Copyrighted I960. If thedevice is used with a proportional spacing typewriter in which each typecharacter has a width in accordance with its natural width, then thebackspace mechanism would be ofthe type shown and described in pages 5|to 58 or the type shown and described in pages 59 and 6t) ofthe IBMCustomer Engineering Instruction Manual for "Executive" Typewriter,Model C-4, Copyrighted 1961.

The backspace lever 26 is connected to a release lever 40 of the camassembly 37 by a cam release link 41 and a cam release lever spring 42.As more particularly shown and described in pages 49 to 52 of theaforesaid IBM Model C-l Manual, the cam assembly 37 has a single lobedcam 43 rotatably mounted thereon for cooperation with the power roll ofthe typewriter. The single lobed cam 43 rotates 360 during eachactuation thereof.

The cam release lever 40 has a primary forward lug and a nonrcpcat lugthereon for cooperation with a cum lug on the cam 43. When the backspacelever 26 is moved to its second level position whereby the plunger 32 ismoved downwardly against the force of the spring 33, the nonrepcat lugof the release lever 40 is maintained out of the path of the cam lug topermit automatic repeat operation of the backspace mechanism. Thiscooperation between the lugs on the cam release lever 40 and the lug onthe cam 43 is particularly described on page 51 of the aforesaid IBMModel C-l Manual. The type of cooperation between the backspace lever 26and nonrepcat lug ofthe cam release lever 40 also is mentioned on page87 of the aforesaid IBM Model C-l Manual with respect to the carriagereturn key lever. This samc operation occurs with the backspace lever26.

Act ordiugly, the initial downward movement of the backspace lever 26results in the lever 26 nicrcly moving the plunger 32 downwardly but notsufficiently to overcome the force of the spring 33. This results in afirst level position for the backspace lever 26 whereby a singleactuation of the backspace mechanism of the typewriter occurs tobackspace the carriage and the platen relative to the reference positionat which the characters are printed. This backspace movement moves themovable member 10 to the left.

When additional force is exerted by the typist on the backspace lever26, the force of the spring 33 is overcome to permit further downwardmovement of the backspace lever 26 to a second level position. In thissecond level position of the backspace lever 26, repeat backspaceoperations of the backspace mechanism occur due to the position of thenonrepeat lug on the release lever 40 until the backspace lever 26 isreleased.

In the present proportional spacing typewriters, the typist must knowthe number of units that each character occupies and backspace thisnumber of units for each character when that character has been erased,for example, due to an error. This may be accomplished by singleactuation of the backspace lever 26 or by the typist holding thebackspace lever 26 in its second level position until the requirednumber of backspace operations has occurred.

The memory backspace device of the present invention utilizes a latch 50to retain the backspace lever 26 in its second level position until therequired number of repeat backspace operations has occurred to move thecarriage to the desired position. For example, if the memory backspacedevice of the present invention is utilized to produce a selected amountof backspacing in accordance with the width of the character previouslytyped, then the latch 50 would retain the backspace lever 26 in itssecond level position until the selected amount of backspacing hasoccurred. Similarly, if :1 word is the selected amount of backspacingdesired, then the latch 50 would retain the lever 26 in its second levelposition until this amount of backspacing has occurred. It should beunderstood that the latch 50 cannot retain the lever 26 in its secondlevel (repeat backspace operation) position until the lever 26 has beenmoved to its second level position by the typist.

The latch 50, which is pivotally mounted on a rod 50, is resilientlybiased into engagement with the lever 26 by a spring 51. However, thelatch 50 abuts against the side of the lever 26 rather than latchingover the top surface thereof in either the normal rest position of thelever 26 or the position of the lever 26 when single actuation isproduced. Thus, the latch 50 cannot affect the operation of thebackspace lever 26 until the lever 26 is moved to its second levelposition whereby automatic repeat backspace operations may occur.

The latch 50 is connected through a cable or wire 52 to the finger 25ofthe memory lever 12. The cable 52, which has one end connected to thelatch 50, is enclosed along its entire length by a sheath 53 (removedalong most of the cable 52 for clarity purposes), which has a portionsupported in a bracket 54 that is fixed to the typewriter frame andclamped to the bracket 54. The other end of the cable 52, which isslidably supported in the sheath 53, is connected to the finger 25 ofthe memory lever 12 by a hook portion 55. The portion 55 extends throughan enlarged opening or elongated slot 57 in the finger 25 of the memorylever 12 and is ofa length to permit pivoting of the memory lever 12about the pin 22 without affecting the position of the cable 52. Thus,only pivotal move-. ment of the lever 12 about the pin 21 is transmittedto the latch 50.

The pivotal movement of the lever 12 about the pin 22 is limited becauseof the engagement of the bottom of the lever 12 with the main surface 19ofthe bracket 11 and engagement of the surface 15 of the frictionalmember 14 with the bottom of the movable member 10. This permits only alimited amount of pivotal movement of the memory lever 12 about the pin22.

The latch 50 is shown in its nonretaining position in FIG. I due to thememory lever 12 engaging the stop 17. In this position of the memorylever 12, the cable or wire 52 holds the latch 50 away from the positionin which it will retain the backspace lever 26 in its second levelposition when the lever 26 is moved to its second level position.

Accordingly, whenever the cable or wire 52 is moved due to clockwisepivoting of the lever 12 about the pin 21 so that the lever 12 movesaway from the stop 17, the latch 50 is moved by the spring 51 to theposition in which the latch 50 abuts against the side of the lever 26.This clockwise pivoting of the lever 12 about the pin 21 occurs when themovable member is moved to the right due to printing occurring becauseof the paper on which the characters are being printed being moved in aforward horizontal direction relative to the reference position at whichcharacters are to be printed.

When the memory lever 12 is returned into engagement with the stop 17 bycounterclockwise pivoting of the lever 12 about the pin 21, the cable 52pulls the latch 50 to its nonretaining position. Thus, the cable 52regulates when the latch 50 is ,moved to and from its nonretainingposition with the lever 12 controlling this regulating means.

When used with a proportional spacing typewriter, the memory lever 12may be moved with the movable member 10 for either the amount ofmovement of the member 10 to the right due to a single character beingtyped or a word being typed. Thus, the selected amount of movement ofthememory lever 12 by the movable member 10 before the memory lever 12 isremoved from engagement therewith may be either the width of thecharacter typed or the width of the word typed. Of course, with aconventional typewriter, the selected amount of movement of the memorylever 12 would only be a word since single actuation of the backspacemeans for a conventional lever would produce the desired amount ofbackspacing for any single typed character.

In moving the memory lever 12 either the amount due to a singlecharacter being typed or a word being typed, the memory lever 12 ismoved to one of a plurality of effective positions from its homeposition, which is the position when the memory lever 12 is engagingagainst the stop 17 and to which it is always returnedWhen the memorylever 12 is disengaged from the movable member 10, it returns to thehome position. Therefore, the memory lever 12 reciprocates between thehome position'and one of the effective positions, which representseither a character or word being typed, to which it is moved duringmovement of the movable member 10.

if the selected amount of movement of the memory lever 12 is the typedword, then the memory lever 12 would be permitted to move with themovable member 10 until after completion of the word. Completion of theword has occurred when a spacebar lever is actuated.

When this occurs. the memory lever 12 is pivoted clockwise about the pin22 and counterclockwise about the pin 21 to return the memory lever 1-2to the position in which it abuts against the stop 17. Of course, whenthe surface of the friction member 14 is removed from engagement withthe movable member 10, the spring 23 also aids in moving the memorylever 12 counterclockwise about the pin 21 so that the pivoting of thememory lever 12 about the pin 21 is both by the operating mechanism,which is responsive to the spacebar lever to exerta pulling force on thememory lever 12, and the spring 23.

The. operating mechanism for removing the surface 15 of the frictionmember 14 from engagement with the movable member 10 and returning thememory lever 12 into engagement with the stop 17 includes a cable orwire 58, which is enclosed within a sheath 59 (partially shown forclarity purposes) and slidably movable therein. The sheath 59 issupported within a curved portion of a bracket 60, which is fixed to anupstanding portion 61 of the bracket 11, and clamped thereto. The cableor wire 58 has one end connected to the memory finger 25 and its otherend directly or indirectly connected to the spacebar mechanism of thetypewriter. Thus, when the spacebar mechanism is actuated by the typistto indicate the end ofa word. the cable or wire 58 pulls the finger 25of the memory lever 12 upwardly and to the right due to the angle offorce exerted by the cable 58 with respect to the finger 25 whereby thelever 12 pivots clockwise about the pin 22 and counterclockwise aboutthe pin 21 to return the lever 12 to the position in which it engagesagainst the stop 17.

As shown in FIG. 1, the other end of the cable 58 is formed as a loopedportion 61a cooperating with a bail 6119, which extends therethrough andis actuated when the spacebar mechanism is actuated by the typist. Thelooped portion 61a of the cable 58 is selected so that the lever 12 maymove from the stop 17 to the stop 16, but the movement of the bail 6112causes return of the lever 12 into engagement with the stop 17.

As soon as the memory lever 12 is moved away from engagement with thestop 17, this initial clockwise movement of the memory lever 12 aboutthe pin 21 results in the cable 52 no longer holding the latch 50 in itsnonretaining position but permits the spring 51 to urge the latch 50into the position in which it abuts against a side of the backspacelever 26. Thus, as soon as the memory lever 12 leaves its abuttingposition against the stop 17, the latch 50 is moved to the position inwhich it may readily retain the backspace lever 26 when the lever 26 isin its second level position.

When the spacebar lever is actuated, the cable or wire 58 returns thememory lever 12 to the position in which it abuts against the stop 17.Thus, the cable 52 pulls the latch 50 clockwise against the force of thespring 51 to dispose the latch 50in a nonretaining position.

When the memory lever 12 is moved away from the stop 17 by the movablemember 10, movement of the backspace lever 26 into its second levelposition wherein automatic repeat backspace operations will occur aslong as the lever 26 is held in this position results in the latch 50retaining the backspace lever 26 in its second level position until thememory lever 12 is returned to the position in which it abuts againstthe stop 17. Thus, as backspacing progresses, the member 10 moves to theleft to return the memory lever 12 into engagement with the stop 17. Assoon as it reaches this position, which indicates the starting positionof the word, the cable 52 pulls the latch 50 to its nonretainingposition to release the backspace lever 26 whereby the backspace lever26 returns to its rest position by the force of the spring 30.

If any of the words being typed should have an exceedingly long length,then the memory lever 12 would abut against the stop 16. Thus, the totalpivotal movement of the memory lever 12 is limited to a predeterminedamount.

If the memory backspace device of the present invention is to beutilized on a proportional spacing typewriter, it might be preferable tomove the memory lever 12 only the width of each typed character. Sincethe width of each of the characters would vary depending on the naturalwidth of the character, this would result in a varying amount ofmovement ofthe memory lever 12 by the movable member 10 depending uponthe natural width of the character being typed.

in this arrangement, the cable 58 would be connected to a portion of themechanism actuated during each actuation of a character key. In orderthat the previously stored character width in the memory device may beremoved, it is preferred to actuate the cable 58 when the ribbon liftbegins to move during selection of a character. This permits thefriction surface 15 of the friction member 14 to be released fromengagement with the movable member 10 and returned to a positionabutting against the stop 17 before the character is printed at thereference position. This arrangement insures that the memory lever 12remains in a position in which the latch 50 abuts against the side ofthc backspace lever 26 with the position of the memory lever 12 from thestop 17 being the number of units of space in accordance with thepreviously typed character until the next character is being selected.

When the lever 12 is to be advanced only the width of the typedcharacter, the bail 61b would be the ribbon lift bail. Thus. the loopedportion 61a of the cable 58 would allow the lever 12 to move from thestop 17 to the stop 16 without the cable 58 retarding movement thereofwhile the actuation of the bail 61b still results in the lever 12 beingreturned into engagement with the stop 17.

Thus, when a character is typed, the memory lever 12 is moved away fromengagement with the stop 17. The lever l2 remains away from the stop 17wherein the latch 50 is held against the side of the backspace lever 26by the spring Sl until the ribbon lift begins to move during selectionof the next character. At this time, the cable 58 and the spring 23 movethe memory lever 12 back to its position against the stop 17 whereby thecable 52 moves the latch 50 to its nonretaining position. Then, as thecharacter is typed, the movable member moves the width of the newcharacter and carries the memory lever 12 therewith away from the stop17.

This movement of the memory lever 12 away from the stop 17 allows thespring 51 to move the latch 50 into engagement with the side of thebackspace lever 26. if at the end of the typed letter, an error is made,depression ofthe backspace lever 26 to its second level position resultsin the latch 50 retaining the backspace lever 26 in its second levelposition until the movable member 10 has moved to the left sufficientlyto return the memory lever l2 into engagement with the stop 17. At thistime, the cable 52 pulls the latch 50 to its nonretaining position andallows the backspace lever 26 to be returned to its rest position.

The memory lever 12 also is returned into engagement with the stop 17when various function operations ofthe typewriter occur. Thus, if acarriage return or tabulation occurs, for example. the memory lever 12is returned into engagement with the stop 17 irrespective of whether thememory lever 12 has been moved the selected amount by the movable member10. This results in removal of the stored memory in the memory lever 12.

The finger 25of the memory lever 12 has one end of a second cable 62connected thereto. The second cable 62 is enclosed within a sheath 63(partially shown for clarity purposes), which is supported in anothercurved portion of the bracket 60 and clamped thereto. The other end ofthe cable 62, which is slidably supported within the sheath 63, isconnected to means responsive to the various function operations. Forexample, the cable or wire 62 could be connected to the carriage returnor to the tabulation lever or be responsive to movement of either.

The other end of the cable 62 may be formed in a looped portion 62acooperating with a bail 6212, which extends therethrough. The bail 62bmay be responsive to any of the various function operations of thetypewriter by having the bail 62b span all of the cams producing thevarious function operations so that the bail 62b is responsive to any ofthe function operations.

Accordingly, when the cable 62 is moved, the lever 12 is pivotedclockwise about the pin 22 to remove the surface of the friction member14 from engagement with the movable member 10, and the lever 12 ispivoted counterclockwise aboutthe pin 21 to return the lever 12 intoabutting engagement with the stop 17. When this occurs, the previouslystored character, word, or portion of the word in the memory lever 12 isremoved. As a result, the return of the memory lever 12 into engagementwith the stop 17 by the cable 62 due to a function operation of thetypewriter results in the latch 50 being moved to its nonretainingposition by the cable 52. Accordingly, depression of the backspace lever26 to its second level position would not result in the backspace lever26 being retained in its second level position by the latch 50.

While the memory lever 12 has the friction surface 15 ofthe frictionmember 14 in engagement with the movable member 10 to follow themovement thereof during backspace operations, it should be understoodthat the friction surface 15 has a coefficient of friction with themember 10 so that manual movcment of the member 10 to the left permitssliding of the member 10 relative to the friction surface 15 when thememory lever 12 abuts against the stop l7. Thus, the memory lever 12does not retard movement ofthe movable member 10 and the connectedplaten. v

Considering the operation ofthe device of FIG. 1, the spring 23 normallyurges the memory lever 12 to the position shown wherein the memory lever12 abuts against the stop 17 and the friction surface l5 of the frictionmember 14 is held in contact with the movable member 10. in thisposition of the memory lever 12, the latch 50 is held in a nonretainingposition by the cable 52 whereby movement of the backspace lever 26 toits second level position does not result in the backspace lever 26being retained in its second level position by the latch 50.

if the selected amount of movement of the memory lever 12 is a typedcharacter, then the memory lever 12 moves with the movable member 10 forthe distance that the movable member 10 moves to type the singlecharacter. Any movement of the memory lever 12 away from the position ofFIG. 1 results in the spring 51 urging the latch 50 into engagement withthe side of the backspace lever 26.

lf an error should be made by the typist in typing the character,erasure of the character may be accomplished by rotating the platen toadvance the paper vertically relatively to the reference position atwhich the character is typed. After the character has been erased andthe paper returned to the position in which the character was printed atthe reference position, it is now necessary to return the platen and thepaper to the position at which printing of the erased character started.Accordingly, depression of the backspace lever 26 to its second levelposition results in the latch 50 retaining the backspace lever 26 inthis position in which automatic repeat backspace operations occur untilthe memory lever 12 has been returned into engagement with the stop 17by the movable member 10. This amount of rearward movement (to the left)by the movable member 10 and the memory lever 12 is equal to the amountof forward movement produced during typing of the character.Accordingly, when the lever 12 abuts against the stop 17, the cable 52exerts a force to pull the latch 50 to its nonretaining position wherebythe backspace lever 26 returns to its rest position due to the force ofthe springs 30 and 33. I

When the memory lever 12 is removed from engagement with the stop 17 bythe movable member 10 to allow the latch 50 to be moved by the spring51, it should be understood that the latch 50 will not retain thebackspace lever 26 until the backspace lever 26 is moved to its secondlevel position. That is, the backspace lever 26 may be depressed againstthe plunger 32 by the typist to a first level position in which singleactuation ofthe backspace mechanism occurs. Thus. the latch 50 permitssingle actuation of the backspace lever 26 even when the latch 50 is inengagement with the backspace lever 26 since the latch 50 cannot retainthe backspace lever 26 until the lever 26 is moved to its second levelposition.

if a word is to be the selected amount of movement of the memory lever12 rather than each typed character, then the cable 58 would beconnected to be responsive to the spacebar means, which is utilizedwhenever a word is completed, rather than being responsive to the ribbonlift mechanism. Thus, the memory lever 12 would be moved by the movablemember 10 until the spacebar means is actuated. When this occurs, thememory device 12 will be returned to the position in which it abutsagainst the stop 17 whereby the latch 50 is held in its nonretainingposition by the cable 52.

With the memory lever 12 being moved by the movable member 10 until theend of a typed word, any error in typing the word could be corrected byerasing the entire word. Then, depression of the backspace lever 26 toits second level position would result in the latch 50 holding the lever26 in this repeat position until the memory lever 12 is returned intoengagement with the stop 17 by the movable member 10 moving to the leftdue to backspacing operation causing the platen carrying the paper onwhich the characters are printed to move to the left.

When the memory lever l2 engages the stop 17, the paper is positioned atthe reference position. This permits typing to begin again where theerased word originally started.

Of course, as described with respect to the memory lever 12 being movedonly the width of a character in a proportional spacing 'typewriterrather than each typed word, the backspace lever 26 may be moved to afirst position in which it abuts against the plunger 32for singlebackspacing without the latch 50 retaining the-backspacing lever 26.However, the latch 50 is disposed in engaging position with the side ofthe backspace lever 26 and will retain the backspace lever 26 wheneverthe backspace lever 26 is moved-to its second level position byovercoming the force of the spring 33 to depress the plunger 32 furtherdownwardly.

Irrespective of whether the memory lever 12 is moved a selected amountdepending on the width of the character typed or the width of the wordtyped, the memory lever 12 is returned to its position against the stop17 whenever the cable 62 is actuated. This results in the latch 50 beingmoved to its nonrctaining position.

By having the cable 62 responsive to various function operations, thestored memory in the memory lever 12 is removed as soon as a functionoperation occurs. Thus, for ex ample, if a carriage return occurs, thecable 62 is actuated to return the memory lever 12 into engagement withthe stop 17. Additionally, this actuation of the cable 62 results-in thefriction surface 15 not engaging the movable member during movement ofthe movable memberlO to the left because of carriage return. While suchmovement would be possible even if the friction surface were engagingthe movable member 10, it is desirable to not have the friction surface15 engaging the movable member 10 to reduce wear of the friction surfaceReferring to FIG. 4, there is shown another embodiment of the backspacememory' device of the present invention in which a memory wheel 70cooperates .with the movable member). The memory wheel 70 has a frictionsurface formed thereon of a suitable friction material, which ispreferably the same as the friction member'14.

The wheel 70 is fixedly mounted on a rotatably mounted shaft 71. One endof the shaft 71 is rotatably supported in a bracket 72, which is fixedlysecured to the frame of the typewriter. The other end of the shaft 71 isrotatably supported by a bellcrank lever 73, which is pivotally mountedon a rod 74. The rod 74 is fixedly secured to the frame of thetypewriter.

A spring 75,-which has one end secured to a fixed portion 76 of theframe of the typewriter and its other end secured to the bellcrank lever73, continuously urges the memory wheel 70 into engagement with themovable member 10. Thus, the memory wheel 70 follows the movement of themovable member 10 as long as the bellcrank lever 73 is held in theposition of FIG. 4 by the spring 75.

When the force of the spring 75 is overcome, the bellcrank lever 73 isrotated counterclockwise about the rod 74 to remove the memory wheel 70from engagement with the movable member 10. A link 77, which is slidablysupported by a bracket 77', is connected to thebellcrank lever 73, andmovement of the link 77 to the right causes the bellcrank lever 73 topivot counterclockwise against the force of the spring 75.

Unless the link 77 is moved to the right, the spring 75 retains thememory wheel 70 in engagement with the movable member 10 whereby thememory wheel 70 rotates clockwise when the movable member 10 moves tothe right and counterclockwise when the movable member 10 moves to theleft. The movement of the movable member 10 to the right occurs when thepaper on which the type characters are printed is being advancedforwardly in a horizontal direction relative to the reference positionat which the type characters are printed. The movement to the left ofthe movable member 10 occurs when backspacing occurs.

The shaft 71 has a pulley 78 fixedly secured thereto forrotationtherewith. Thus, any rotation of the shaft 71 by the memorywheel 70 is transmitted to the pulley 78.

A tape 79 passes around the pulley 78 and also passes around an idlerpulley 80, which is rotatably mounted on a rod 84 in a bracket 85, whichalso is fixed to the frame of the typewriter. A tape spring 86 surroundsthe tape 79 and has one end fixed to the bracket 83. The other end ofthe tape spring 86 bears against a bead 87 on the tape 79 with the bead87 being larger than the opening 84. As the memory wheel 70 is rotatedclockwise, the tape spring 86 is compressed by the bead 87 moving towardthe bracket 83.

The tape 79 has a second bead 88 thereon for cooperation with a latch89, which cooperates with the backspace lever 26 to retain the backspacelever 26 in its second level position when the latch 89 is in itsretaining position and the backspace lever 26 is in its second levelposition. The latch 89 is formed of resilient material so that it isspring biased into engagement with the backspace lever 26:

The latch 89 has an opening 90 therein through which the tape 79 passes.However, the size of the opening 90 prevents the bead 88 from passingtherethrough. Accordingly. when the bead 88 engages the latch 89, thelatch 89 has its resilient force overcome and is removed from itsposition against the side of the backspace lever 26.

Accordingly, clockwise rotation of the memory wheel 70 by the movablemember 10 moves the bead 88 away from engagement with the latch 89whereby the latch 89 abuts against the side of the backspace lever 26for movement to its retaining position when the backspace lever 26 ismoved to its second level position. This clockwise rotation of thememory wheel 70 also results in the tape spring 86 being compressed bythe bead 87. This occurs when characters are being typed.

When the movable member 10 is moved to the left (This is backspacemovement), the memory wheel 70 is moved counterclockwise by the member10 whereby the bead 88 is eventually moved into engagement with thelatch 89 to remove it from its retaining position. This occurs when thebackspace lever 26 is depressed.

Theembodiment of FIG. 4 is shown for use with a proportional spacingtypewriter in which the width of each character is designed inaccordance with its natural width. Thus, the memory backspace device ofFIG. 4 contemplates the memory backspace device storing either acharacter or a word in accordance with the desire of the typist.

As previously mentioned, movement of the link 77 to the right removesthe memory wheel 70 from engagement with the movable member 10. Whenthis occurs, the tape spring 86 causes counterclockwise rotation of thememory wheel 70 and the pulley 78 until the bead 87 engages the bracket85. When this occurs, the bead 88 has moved the latch 89 to itsnonretaining position.

The link 77 may be moved to the right whenever an annular member 91 onthe link 77 is engaged by an arm 92, which is pivotally mounted by a pin92a on a bifurcated member 9211, or an arm 93, which is pivotallymounted by a pin 93a on a bifurcated member 93b, and moved to the right.The arm 92 is responsive to the movements of the ribbon lift mechanismand extends through an opening in a pivotally mounted lever 94. Thelever 94, which has the link 77 passing through an elongated slot 95therein, is shown in FIG. 4 in position to have a finger 96 on the arm92 disposed for engagement with the annular member 91. Thus, in theposition shown in FIG. 4, each movement of the ribbon lift mechanismresults in the link 77 being moved to the right due to the arm 92 beingmoved to the right whereby the finger 96 pulls the annular member 9ltherewith.

A resiliently biased latch 97 is disposed in a notch 98 in a top surfaceof the lever 94 in the position of FIG. 4. In this position, the lever94 is retained by the latch 97 so as to insure that the finger 96 of thearm 92 engages the annular member 91.

When the latch 97 is disposed in a notch 99 in the lever 94 due toleftward movement of the lever 94, a finger 100 on the arm 93 engagesthe annular member 91 of the link'77 rather than the finger 96 of thearm 92. The arm 93 is connected to the spacebar lever of the typewriterwhereby each actuation of the spacebar lever moves the arm 93 to theright. As a result, the finger 100 moves the annular member 91 and theconnecting link 77 to the right whereby the bellcrank lever 73 ispivoted counterclockwise to remove the memory wheel 70 from engagementwith the movable member 10.

Accordingly, the embodiment of'FlG. 4 permits the typist to determinewhether the memory backspace device is effective for each character orfor each word typed. it should be understood that the lever 94 would beconnected by suitable means to a mechanism disposed on the exterior ofthe typewriter for actuation by the typist.

As shown in FIG. 4, the lever 94 has a rod 100a disposed in one endthereof and connected to a control lever 10017, which is exterior of thetypewriter frame for actuation by the typist. The control lever ispivotally supported on a rod [000. Accordingly, when the control lever10Gb pivots about the axis of the rod 1000, the lever 94 also pivotsabout the axis of the rod 1000 to move longitudinally from the positionof FIG. 4 to the left.

Considering the operation of the memory backspace device of FIG. 4 withthe lever 94 in the position shown in FIG. 4, movement of the movablemember 10 to the right during typing operations causes clockwiserotation of the memory wheel 70. Clockwise rotation of the memory wheel70 results in the bead 88 being removed away from the latch 89 as soonas the movable member 10 moves. As the actuation of the next characterkey results in the ribbon lift a result, the latch 89 moves to theposition in which it abuts against the side of the backspace lever 26.This clockwise movement of the memory wheel 70 causes compression of thetape spring 86.

With the lever 94 positioned for each character to be the selectedamount of movement of the memory wheel 70, the actuation of the nextcharacter key results in the ribbon lift mechanism causing the link 77to move to the right through the arm 92 whereby the memory wheel 70 isreleased from engagement with the movable member 10 before printing ofthe next character but during actuation thereof. As soon as the memorywheel 70 is released from engagement with the movable member 10 due tocounterclockwise pivoting of the bellcrank lever 73, the tape spring 86rotates the pulley 78 and the memory wheel 70 counterclockwise until thebead 87 engages the bracket 85. This movement of the tape spring 86returns the bead 88 into engagement with the latch 89 to move the latch89 to its nonretaining position.

When the next character is printed, the movement of the movable member10 to the right again causes clockwise rotation of the memory wheel 70.This again removes the bead 88 from engagement with the latch 89 toallow the latch 89 to be disposed against the side of the backspacelever 26.

If an error should occur when typing this letter, the typist wouldvertically move the paper relative to the reference or printing positionby rotating the platen and erase the character. Then, the paper wouldagain be properly aligned to permit printing of a character thereon. Atthis time, the typist would depress the backspace lever 26 to its secondlevel position by overcoming the force of the spring 33. When thebackspace lever 26 moves to its second level position, the latch 89would retain the backspace lever 26 in this second level position untilbackspacing is completed for the particular width of the previouslytyped character.

Each actuation of the backspacing mechanism moves the movable member 10to the left whereby the memory wheel 70 rotates counterclockwise andmoves the head 88 closer to the latch 89. When the final backspaceoccurs, the bead 88 engages the latch 89 to move the latch 89 to itsnonretaining position and release the backspace lever 26. At this time,the typist may type the correct character.

If the typist wishes to utilize the memory backspace device for onlywords, then the lever 94 is moved so that the latch 97 is disposed inthe notch 99. At this time, the arm 93 has the I finger 100 of the-arm93 whereby the memory wheel 70 is released from engagement with themovable member 10. The compressed tape spring 86 then rotates the pulley78 and the memory wheel 70 counterclockwise until the bead 87 engagesthe bracket 85. At this time, the bead 88 has engaged the latch 87 tomove it to its nonretaining position.

When typing of another word begins, the memory wheel 70 is again rotatedclockwise by the movable member 10 moving to the right to again removethe bead 88 from engagement with the latch 89. This permits the latch 89to again return to the position in which it may retain the backspacelever 26 in its second level position when the lever 26 is moved to thisposition.

If the typist should make an error in the work, the paper is movedvertically by rotating thv platen to permit erasure of the entire work.Then, the paper is again returned to the position in which printingoccurs.

Depression of the backspace lever 26 to its second level position atthis time results in the backspace lever 26 being retained by the latch89 until there has been sufficient rearward horizontal movement of thepaper on which the characters are printed relative to the referenceposition at which the characters are typed. When the rearward relativehorizontal movement has resulted in the paper being positioned so thattyping may occur where the word previously began, the head 88 hasengaged the latch 89 to move it to its nonretaining position. At thistime, the backspace lever 26 is returned to its rest position by thespring 33.

During backspacing by the backspace means, the movable member 10 movesto the left. Due to this movement of the movable member 10 to the left,the memory wheel 70 rotates counterclockwise to eventually return thehead 88 into engagement with the latch 89.

If it is desired to return the latch 89 to its nonretaining positionduring each function operation ofthc typewriter irrespective of theselected amount of movement of the memory wheel 70, the link 77 may havea second annular member 101 thereon for cooperation with a finger 102 onan arm 103. Thus, when the arm 103 is moved to the right, the link 77 ispulled to the right whereby the memory wheel 70 is released fromengagement with the movable member 10. As a result, the tape spring 86returns the tape 79 to the position in which the bead 88 engages thelatch 89 to return the latch 89 to its nonretaining position.

The arm 103 may be made responsive to any desired functional operationof the typewriter. For example, the arm 103 could be responsive totabulation or carriage return, for example. The connection to the arm103 could be in such a manner that it could be responsive to either ofthese function operations if desired.

It should be understood that the amount of pivotal movement of thebellcrank lever 73 is very slight. The shaft 71 is rotatably supportedin the fixed bracket 72 so that the actual amount of movement of theshaft 71 is quite limited.

When the bead 88 is in engagement with the latch 89, the memory wheel 70is at its start or home position to which it always returns. The memorywheel 70 is moved by the movable member 10 to one of a plurality ofeffective positions depending upon whether the memory wheel 70 isrotated a distance equal to the width ofa typed character or the widthofa typed word; thus, the memory wheel 70 is advanced to a plurality ofeffective positions from its home position.

The memory wheel 70 is returned to the home position when the memorywheel 70 is disengaged from' the movable member 10. Thus, the memorywheel.70 reciprocates between its home position and one of the effectivepositions to which it bead 88 into engagement with the latch 89 and thebead87 into engagement with the bracket 85. This removes any storedmemory in the device.

The engagement of the bead 88 with the latch 89 and the bead 87 with thebracket 85 stops further counterclockwise rotation of the shaft- 71 dueto the wheel 70 being rotated counterclockwise by the movement of themember to the ,left. As a result, traction engagement between themovable member 10 and the wheel 70 ceases because of the wheel70 beingprevented fromrotating. This breaking of the traction engagement betweenthe movable member 10 and the wheel 70 results in the movable member 10continuing to move to the left without any rotation of the wheel 70.

While the embodiment of FIG. 1 has been described for controlling theamount of movement of the memory lever 12 in accordance with onlythewidth of the typed character or a typed word depending on whether thecable 58 is connected only to the ribbon lift mechanism orthe spacebarmeans ofthe typewriter. it should be understood that the cable 58 may hemade responsive to either the ribbon mechanism or the 'spacebar means asdescribed for the modification of FlG. 4. Thus, suitable means would beemployed to cooperate with the cable 58 to actuate it in response toeither the ribbon lift mechanism or the spacebar means in accordancewith means controlled by the typist.

Referring to FIG. 5, there is shown an arrangement for actuating thecable 58 in response to either the ribbon lift mechanism or the spacebar means. The cable 58 is connected to a link 110 with an annularmember 111 on one end thereof. The link 110 is pivotally connected tothe cable 58 for movement by a control lever 112, which the typistcontrols, between a position in which the annular member 111 may beengaged by a finger 113 on an arm 114 and a position in which theannular member 111 may be engaged by a finger 115 on an arm 116.

The arm 114 is responsive to the movement of the ribbon lift mechanism.Thus, each movement of the ribbon lift mechanism in the link 110 beingmoved to the right due to the arm 114 being moved to the right when thelink 110 is disposed so that the finger 113 can engage the annularmember 111 when the arm 114 moves to the right. This pulls the cable 58to return the memory lever 12 into engagement with the stop 17.

The arm 116 is connected to the space bar lever of the typewriterwhereby each actuation of the space bar lever moves the arm 116 to theright. As a result, when the link 110 is positioned so that the finger115 can engage the annular member 111 when the arm 116 moves to theright, the connecting link 110 is moved to the right whereby the cable58 is pulled to return the memory lever 12 into engagement with the stop17.

The lever 112 is connected to the link 110through a cable 117, which isslidably supported within a shaft] 18 that is fixed against movement.Thus, movement of the control lever 112 in one direction positions theannular member 111 where it can be engaged by the finger 113 whilemovement in the op posite direction of the control lever 112 disposesthe annular member 111 for engagement by the finger 115.

While the memory backspace device of the present invention has beendescribed with respect to a typewriter in which a carriage has a platenmovable therewith for carrying the paper for printing with the carriageand platen being movable relative to the printing position, it should beunderstood that the memory backspace device of the present inventioncould be utilized with a typewriter of the single element printing headtype such as the typewriter shown and described in US. Pat. No.2,9l9,002 to Palmer. 1n the aforestid Palmer patent, the

paper and platen do not move but the carrier having the single elementprinting head thereon moves. Furthermore, the direction of movement isopposite to that of the carriage. That is, forward relative horizontalmovement between the carrier and thereference or printing position atwhich printing occurs would be to the left in FIGS. 1 and 4 whilerearward relative horizontal movement is to the right. Thus, it would benecessary to appropriately design the memory backspace devices to beresponsive to movements in the opposite direction,

in a single element printing head typewriter, the movable member 10would probably be connected to the carrier tape, which moves the carrierand is connected thereto. it is only necessary that the movable member10 be responsive to the relative horizontal movement between the carrierand the reference or printing position at which the type characters areprinted.

While the memory backspace device of the present invention has beendescribed with respect ta typewriter. it should be understood that thedevice could be employed with any printing apparatus. While the device Ias been described with respect to a single backspace key mm ible to twopositions, it should be understood that it may be employed with anybackspace means of a printing apparatus that will permit backspaceoperations.

An advantage of this invention is that it is relatively inexpensive andmay be easily attached to a typewriter. Another advantage of thisinvention is that it eliminates the complicated pin wheel memory devicefor backspacing. A further advantage of this invention is that itpermits utilization of a single backspace key for both normal singleunit backspacing and automatic backspacing under control of the memorybackspace device.

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that the foregoing and other changes in formand details may be made therein without departing from the spirit andscope of the invention.

lclaim:

1. A memory backspace devicefor a printing apparatus having meansmovable during each relative horizontal movement between a referenceposition at which a character may be printed and paper on which thecharacters are printed and backspace means to cause rearward relativehorizontal movement between the reference position at which charactersmay be printed and the paper. on which the characters are printed duringeach actuation of the backspace means, said devicc comprising:

means to cooperate with the backspace means for retaining the backspacemeans in a position for backspace opera tion; means to regulate whensaid cooperating means is moved to a nonretaining position during abackspace operation;

means to control said regulating means to determine when said regulatingmeans moves said cooperating means to its nonretaining position during abackspace operation;

means releasably connecting said control means to the movable means ofthe printing apparatus to move said control means from a home positionin response to forward relative horizontal movement between thereference position at which characters may be printed and the paper onwhich the characters are printed and to return said control means to itshome position when a selected amount of backspacing occurs to move saidcooperating means to its nonretaining position during a backspaceoperation; and

means to return saidcontrol means to its home position when apredetermined operation of the printing apparatus occurs after aselected amount of forward relative horizontal movement occurs betweenthe reference position at which characters may be printed and the paperon which the characters are printed.

2. The device according to claim 1 in which said control means is areciprocatingmeans that reciprocates between its home position and theposition to which it is advanced by the movable means ofthe printingapparatus.

3 The device according to claim 1 in which additional means returns saidcontrol means to its home position when a selected function operation ofthe printing apparatus occurs irrespective of the amount of forwardrelative horizontal movement between the reference position and thepaper.

4. The device according to claim 1 in which said return means includesmeans responsive to each selection of a character, said return meansreturns said control means to its home position during each selectionofa character for printing whereby the selected amount of movement isthe width of each selected character.

5. The device according to claim I in which said return means includesmeans responsive to each actuation of forward spacing means of theprinting appara us, said return means returns said control means to itshome position during each actuation of forward spacing means of theprinting apparatus whereby the selected amount of movement is eachprinted word.

6. The device according to claim 1 including, means to determine theselected amount of movement; 5: id determining means including:

first means responsive to each selection of a character for printing andcooperating with said control means whereby the selected amountot'movement is the width of the selected character;

second means responsive to each actuation of forward spacing means ofthe printing apparatus and cooperating with said control means wherebythe selected amount of movement is each printed wordj and third means torender only one of said first and second means operative and to renderthe other of said first and second means inoperative.

7. A memory backspace device for a printing apparatus having meansmovable during each relative horizontal movement between a referenceposition at which a character may be printed and paper on which thecharacters are printed and backspace means tocause rearward relativehorizontal movement between the reference position at which charactersmay be printed and the paper on which the characters are printed duringeach actuation of the backspace means, said device comprising:

means to cooperate with the backspace means for retaining the backspacemeans in a position for backspace operation;

means to urge said cooperating means toward its retaining position;

means connected to said cooperating means for positioning saidcooperating means in a nonretaining position whenever said connectedmeans is in a home position;

means releasably connecting said connected means to the movable means ofthe printing apparatus to move said connected means from its homeposition in response to forward relative horizontal movement between thereference position at which a character may be printed and the paper onwhich the characters are printed whereby said urging means moves saidcooperating means toward its retaining position; and

means to return said connected means to its home position after aselected amount of movement of said connected means by the movable meansofthe printing apparatus.

8. The device according to claim 7 in which said return means includesmeans responsive to each selection of a character for printing wherebythe selected amount of movement of said connected means is the width ofeach selected character.

9. The device according to claim 7 in which said return means includesmeans responsive to each actuation of forward spacing means of theprinting apparatus whereby the selected amount of movement of saidconnected means is each printed word.

it). The device according to claim 7 including additional means toreturn said connected means to its home position in response to any of aplurality of function operations of the printing apparatus irrespectiveof whether said connected means has been moved a selected amount.

11. The device according to claim 7 including. means to determine whenactuation of said return means occurs; said determining means including:

first means responsive to each selection of a character for printingwhereby the selected amount of movement of said connected means is thewidth of the selected character;

second means responsive to each actuation of forward spacing of theprinting apparatus whereby the selected amount of movement of saidconnected means is each printed word; and

third means to render only one of said first and second means operativeand to render the other of said first and second means inoperative.

12. A memory backspace device for a printing apparatus having meansmovable during each relative horizontal movement between a referenceposition at which a character may be printed and paper on which thecharacters are printed and backspace means to cause rearward relativehorizontal movement between the reference position at which charactersmay be printed and the paper on which the characters are printed duringeach actuation of the backspace means, the backspace means being movableto a first position in which single actuation of the backspace meansoccurs and a second position in which automatic repeat operation of thebackspace means occurs, said device comprising:

reciprocating means movable from a home position;

means releasably connecting said reciprocating means to the movablemeans of the printing apparatus to move said reciprocating means fromits home position when there is forward relative horizontal movementbetween the reference position at which a character may be printed andthe paper on which the characters are printed;

means to return said reciprocating means to its home position after aselected amount of movement of said reciprocating means by the movablemeans of the printing apparatus;

means responsive to movements of said reciprocating means andcooperating with the backspace means of the printing apparatus, saidresponsive means being movable from a nonretaining position to a secondposition when said reciprocating means is moved from its home positionwhereby said responsive means moves from its second position to retainthe backspace means in a position for automatic repeat backspaceoperations when the backspace means is moved to its automatic repeatoperation position; and

said responsive means having means to retain the backspace means in aposition for the automatic repeat backspace operations only when thebackspace means is moved to its automatic repeat operation position sothat the backspace means can move to its first position for singleactuation when said responsive means is in both its nonretaining andsecond positions.

13. The device according to claim 12 in which, said responsivc meanscomprises:

a latch biased toward its second position and the position in which itretains the backspace means; and

means connecting said latch to said reciprocating means,

said connecting means holding said latch in its nonretaining positionwhen said reciprocating means is in its home position.

14. The device according to claim 12 in which said return means includesmeans responsive to each selection of a character for printing wherebythe selected amount of movement of said movable means is the width ofeach selected character.

15. The device according to claim 12 in which said return means includesmeans responsive to each actuation of spacing means of the printingapparatus whereby the selected amount of movement of said movable meansis each printed word.

16. The device according to claim 12 including means to determine whenactuation of said return means occurs; said determining means including:

first means responsive to each selection of a character for printingwhereby the selected amount of movement of said reciprocating means isthe width of the selected character;

second means responsive to each actuation of spacing means of theprinting apparatus whereby the selected amount of movement of saidreciprocating means is each printed word; and

third means to render only one of said first and second means operativeand to render the other of said first and second means inoperative.

17. The device according to claim 12 in which:

said reciprocating means comprises a universally pivotally mountedmember;

first resilient means urging said member into engagement with themovable means ofthe printing apparatus; and

said return means comprises:

second resilient means urging said member to its home position; and

means to overcome said first resilient means to remove said member fromengagement with the movable means of the printing apparatus whereby saidsecond resilient means returns said member to its home position.

18. The device according to clai n 12 in which, said reciprocating meanscomprises a rotatably mounted member:

first resilient means urging said member into engagement with themovablemeans of the printing apparatus; and

said return means comprises:

second resilient means urging said member to its home position; and

means to overcomesaid first resilient means to remove said member fromengagement with 'the movable means of the printing apparatus wherebysaid second resilient means returns said member to its home position.

19. The device according to claim l2 including means to limit the amountof movement of said reciprocating means from its home position by themovablt means of the printing apparatus.

20. The device according to claim [2 including additional means toreturn said reciprocating means to its home position in response to anyof a plurality of function operations of the printing apparatusirrespective of whether said reciprocating means has been moved aselected amount.

21. In a printing apparatus having a movable letter feeding part and abackspace key, a memory backspace system wherein the improvementcomprises;

a control member rcleasably cngageable with said letter feeding part; I

means supporting said control member for reciprocating movement betweena home position and a plurality of effective positions;

means operative in conjunction with each printing operation of saidprinting apparatus for sequentially disengaging and then engaging saidcontrol member with said letter feeding part to move said control memberto said home position and then to one of said effective positions, saidone effective position being representative of forward movement of saidletter feeding part occurring during the conjunctive printing operation;

backspace drive means for moving said letter feeding part in thebackspace direction in response to depression of said backspace key; and

means responsive to said effective position of said control member forgoverning said backspace drive means to move said letter feeding part anamount equal to the forward movement of which said effective position isrepresentative.

.22. in a printing apparatus having a movable letter feeding part and abackspace key, a memory backspace system wherein the improvementcomprises:

a control member releasably engageable with said letter feeding part;means supporting said control member for reciprocating m wement betweena home position and a plurality of effe tive positions;

oper ttive means to disengage said control member from ongagement withsaid letter feeding part after said control member reaches one of saideffective positions and a selected operation of the printing apparatusoccurs to return said control member to its home position and then toengage said control member with said letter feeding part for movement bysaid letter feeding part to one of said effective positions;

backspace drive means for moving said-letter feeding part in thebackspace direction in response to depression of said backspace key; and

means responsive to s'aid effective position of said control member forgoverning said backspace drive means to move said letteF feeding part anamount equal to the forward movement of which said effective position isrepresentative.

23. The improvement according to claim 22 in which said operative meansincludes means responsive to each actuation of forward spacing means ofthe printing apparatus.

24. The improvement according to claim 22 including additional means todisengage said control member from engagement with said letter feedingpart when a selected function operation of the printing apparatus occursirrespective of the position of said control member.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,537,564 November 3, 197( James M. Huckabee It is certified that errorappears in the above identified patent and that said Letters Patent arehereby corrected as shown below:

In the abstract, line 12, "proportioned" should read proportional Column2, line 14, "back spacing" should read backspacing Column 7, line 19,cancel the comma, first occurrence; Column 10, line 18, the colon shouldbe a period. Column 11, line 30, cancel "the actuation of the next";line 31, cancel "character key results in the'ribbon lift". Column 13,line 45 after "mechanism" insert results Column 15, line 22, the commashould read a colon; line 22, "means" should be the start of aparagraph; line 23, "said" should be the start of a paragraph; line 25,"first" should be the start of a subparagraph; line 29, "second" shouldbe the start of a sub-paragrapl line 33, "third" should be the start ofa sub-paragraph. Column 16, line 6, the comma should be a colon; line 6,"means" should be the start of a paragraph; line 7, "said" should be thestart of a paragraph; line 9, "first" should be the start of asub-paragraph; line 14, "second" should be the start of a sub-paragraph;line 18, "third" should be the start of a sub-paragraph; line 63, thecomma should be a colon; line 63, "said" should be the start of aparagraph; line 65, "a" should be the-start of a subparagraph; line 67,"means" should be the start of a sub-paragraph. Column 17 line 5, after"including" insert a colon; line 5, "means" should be the start of aparagraph; line 6, "said" should be the start of a paragraph; line 8,"first" should be the start of a subparagraph; line 12, "second" shouldbe the start of a sub-paragraipl line 16, "third" should be the start ofa sub-paragraph; line 33, the comma should be a colon; line 33, "said"should be the start 0: a paragraph; line 34, the colon should be asemi-colon.

Signed and sealed this 13th day of April 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, J] Attesting OfficerCommissioner of Patent:

